Rotordynamic analysis of a vertical pump with tilting-pad journal bearings

White, Maurice F.; Torbergsen, Erik; Lumpkin, Victor A

doi:10.1016/s0043-1648(96)07469-8

Cited by 24 publications

(16 citation statements)

References 1 publication

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“…To perform simulations of unbalance response in vertical machines it requires that bearing parameters are updated in each time step with respect to eccentricity and load angle, which is time consuming. Cardinali et al [1] have performed nonlinear simulations of a vertical hydropower unit with tilting-pad bearings and White et al [15] performed simulations of a vertical pump with tilting-pad bearings.…”

Section: Introductionmentioning

confidence: 99%

Experimental and Numerical Simulation of Unbalance Response in Vertical Test Rig with Tilting-Pad Bearings

Nässelqvist

Gustavsson

Aidanpää

2014

International Journal of Rotating Machinery

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In vertically oriented machines with journal bearing, there are no predefined static radial loads, such as dead weight for horizontal rotor. Most of the commercial software is designed to calculate rotordynamic and bearing properties based on machines with a horizontally oriented rotor; that is, the bearing properties are calculated at a static eccentricity. For tilting-pad bearings, there are no existing analytical expressions for bearing parameters and the bearing parameters are dependent on eccentricity and load angle. The objective of this paper is to present a simplified method to perform numerical simulations on vertical rotors including bearing parameters. Instead of recalculating the bearing parameters in each time step polynomials are used to represent the bearing parameters for present eccentricities and load angles. Numerical results are compared with results from tests performed in a test rig. The test rig consists of two guide bearings and a midspan rotor. The guide bearings are 4-pad tilting-pad bearings. Shaft displacement and strains in the bearing bracket are measured to determine the test rig's properties. The comparison between measurements and simulated results shows small deviations in absolute displacement and load levels, which can be expected due to difficulties in calculating exact bearing parameters.

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Section: Introductionmentioning

confidence: 99%

Experimental and Numerical Simulation of Unbalance Response in Vertical Test Rig with Tilting-Pad Bearings

Nässelqvist

Gustavsson

Aidanpää

2014

International Journal of Rotating Machinery

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“…White et al [6] have compared two different methods to calculate the force of tilting-pad bearings, using a linear approach characterized by the calculation of stiffness and damping coefficients, and a nonlinear simulation solving the Reynolds equation through analytical approach, and then integrating the pressure numerically to obtain the forces. Both methods could predict that smaller clearances, in the vertical rotor analyzed, could avoid instability effects in the operation's speed range, which was confirmed by experimental tests.…”

Section: Introductionmentioning

confidence: 99%

Rotordynamic analysis of systems with a non-linear model of tilting pad bearings including turbulence effects

Okabe

Cavalca

2008

Nonlinear Dyn

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An analytical model of a tilting pad bearing was developed based on the short bearing assumption with the turbulence effect included. In order to determine its influence on the dynamic behavior of the rotor, this model was compared against one without the turbulence effect through a simulation of a Jeffcott/Laval rotor supported by a couple of bearings. Both models were also used to determine the influence of geometric parameters on tilting pad bearing making use of the aforementioned system at different rotor speeds.When analyzing the results, the parameters which presented the largest influence were: pad preload, number of segments, radial clearance, pad position, and pad pivoting angle. As the pad moment of inertia and the pivoting distance have changed the shaft motion only a few microns, their effects can be neglected. The bearing model with turbulent flow effect has generated higher hydrodynamic forces when compared to the one without this effect, which remarks the importance of considering such phenomenon during the analysis of the high speed hydrodynamic bearings.

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“…Lu et al [10] investigated the nonlinear dynamic behavior of a rigid rotor supported by fixed-tilting-pad journal bearings and analyzed the effects of pivot offsets and preload factors on journal center orbits. White et al [11] investigated the effect of bearing clearances on the rotor dynamic behavior that includes whirl orbits and frequency spectrums of a twelve stage vertical pump rotor with and without the wear ring effect. Monmousseau et al [12] performed a transient thermoelastohydrodynamic (TEHD) analysis on the shaft orbit, minimum film thickness, maximum pressure, and maximum temperature for different unbalance eccentricities.…”

Section: Introductionmentioning

confidence: 99%

Nonlinear dynamic analysis of low viscosity fluid-lubricated tilting-pad journal bearing for different design parameters

Jin

Chen

et al. 2019

Friction

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To reveal nonlinear dynamic rules of low viscosity fluid-lubricated tilting-pad journal bearings (TPJBs), the effects of design parameters on journal center orbits and dynamic minimum film thicknesses of waterlubricated TPJBs with and without static loads are investigated. The hydrodynamic bearing force used in the nonlinear dynamic analysis is an approximate analytical solution including the turbulence effect. The results reveal the methods for vibration suppression and load capacity improvement and give an optimal pivot offset and clearance ratio that can maximize the minimum film thickness. The results also show that four-pad TPJBs with loads between pads are preferred due to good dynamic performance and load capacity. This study would provide some guidance for nonlinear design of low viscosity fluid-lubricated TPJBs under dynamic loads.

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Rotordynamic analysis of a vertical pump with tilting-pad journal bearings

Cited by 24 publications

References 1 publication

Experimental and Numerical Simulation of Unbalance Response in Vertical Test Rig with Tilting-Pad Bearings

Experimental and Numerical Simulation of Unbalance Response in Vertical Test Rig with Tilting-Pad Bearings

Rotordynamic analysis of systems with a non-linear model of tilting pad bearings including turbulence effects

Nonlinear dynamic analysis of low viscosity fluid-lubricated tilting-pad journal bearing for different design parameters

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